Document pmaBXjNO4KX2L7dZ5D5KM5Ow6

I July, tW J HEALTH HAZARDS IN FOUNDRY INDUSTRY 243 (or infhiensa, tuberculosis (all forms), for foundry workers for each of the tod other diseases of the respiratory respiratory diseases throughout the TABLE V Death* from Reapiratost Diabases' raa 1,000 Lira Year* Exposes (Comeihed Group Mortalitt Expbbisbcb 1023-1930); All Aoes tflilff un TIAM lllTI MAT! IHiiItilActfmMt Ill 1J09 MftUAtmtl omr Steel and iron foundries......................................... 430,012 Sliest metsl products (stamping and pressing)...... 209,190 Light metsl produetsjtools, hardware, etc.)......... 1,070,390 Heavy machinery and ether beery metsl produets. 920,024 Bituminous eoai mining--underground.................. 103,407 All industries................................................I........ 30,333,309 3.39 1.43 1.03 1.03 1.04 1.45 33.9 23.0 22.7 33.1 15.5 20.9 * Influent* tad tuberculosis (all forms) art iaeiudsd. TABLE VI Dbatks prow RsariRATORT Diseases* rsm 1,000 Ltrs Years Exposed (Coubined Oroop Mortamtt Experixhce 1923-1930) (A) Btssl sod iroo foundry saployees--(50,012 years of tils exposed. (B) All industrial-- 20,303,369 yean of life exposed 1 euitib * * torUr iwiumT IIIIAIII* A B t A/B tmt nu AB f(nAUns mnmon) AB It a mn IMWIAHfWMT TmOoSTer tRmoImI.UtiIukIImAfaTiaU- A A B At/uBt 18 1.12 0.70 147 0.14 0.04 0.19 0.45 0.79 0.20 34.8 32.8 106 23 1.67 0.03 201 0.00 0.04 0.43 0.61 1.14 0.27 44.0 32.6 135 28 2.09 0.80 243 0.00 0.04 0.57 0.40 1.45 0.34 48.7 30.8 138 33 2.67 0.97 305 0.11 0.06 0.91 0.45 1.55 0.45 31.7 29.3 177 38 3.25 1.24 362 0.10 0.00 0.87 0.51 2.23 0.65 47.3 27.8 170 43 3.63 1.53 233 0.39 0.10 0.89 0.57 2.35 0.06 40.6 24.7 164 40 4.31 1.91 220 0.21 0.R 1.00 0.04 3.10 1.16 30.3 21.8 104 S3 0.00 2.31 230 0.19 0.13 1.30 0.65 3.83 1.50 33.0 18.1 182 so 5.73 3.96 193 0.30 0.33 1.19 0.06 4. IS 2.11 20.5 10.1 104 63 7.04 4.09 107 0.47 0.30 1.01 0.00 6.10 3.99 31.9 13.7 139 00 9.60 5.40 178 0.00 0.42 1.35 0.01 7.43 4.17 18.2 12.4 147 73 U.S1 7.04 147 0.68 0.78 1.03 0.75 9.81 6.31 14.5 12.3 119 73 and over 15.10 12.40 123 0.79 1.19 0.79 0.77 13.01 10.44 12.7 11.8 110 All ages 1.39 1.40 334 0.18 0.10 0.83 0.54 3.33 0.83 33.9 20.9 102 * Includes tuberculosis (all forms) sad influents. system, as well as for this group of working period of life. Foundrymcn causes as a whole. have a rate for infiuensa lower than The striking faot brought out by this that for all workers combined only at table is the uniformly high death rates. eentral age 73, their rate for tubereu* asOuhTj.-/ zn iD ia zt *lV|:lD I'-0k j w .-u v i a >:qj a ? ;' J ii#O ~;i iiI.1 in h ':a;l .40I v: ; f.-ll'l I HD'oris-ad ^ A u fU S cl-j c io m j sT O -as v s i s ir . * ao $ ul,,, lSMI HEALTH HAZARDS IN FOUNDRY INDUSTRY 235 ymraetrical, small, circumscribed, ense areas throughout both lungs, nd later larger masses accumulate. 'bird stage: this differs from the econd stage only in the extent of lung ivolvement, indicated by increased umbers of deposits and more massive rouping. There were 130 employees of the rey iron foundries selected for X-ray seminations of the chest. Of these 1 'as diagnosed as second degree sili* osis, 31 as first degree, 20 as doubtful ir silicosis, and 78 negative for licosis; of 62 employees in the steel sundries, 2 were diagnosed as second egree silicosis, 25 as first degree, 8 as oubtful, and 29 as negative; of 18 mployees of the malleable iron found* es, 7 were diagnosed as first degree, as doubtful, and 9 as negative, and f 5 employees of the non-ferrous letal foundries examined, 1 was iagnosed as first degree, 1 as doubtful, nd 3 as negative. The management of each foundry as furnished with a table setting >rth a detailed description of the 1-ray examination of each worker, srrelatcd with his age, occupation, revious occupation, years of exposure, id other pertinent information indi* sting the extent of the health hazard, he name of the worker waa omitted ad a number substituted in order to void any discrimination. Tables II, III, and IV give the suits of the X-ray examinations by ;e groups, by yean of exposure, and f occupations for the groups exnined. It is obvious that these tables erely indicate what may be expected id are of no statistical value because >e examinations were limited to a few worken only in each group. The individual was classified either accord ing to the department in which ha worked at the time of examination or where he had spent most of his time. Many had changed from one depart ment to another and from one plant to another during their yean of employment in the foundry industry. Since only the amounts of dust col lected at the time of this survey in the various departments are knotvn, there is no way of determining the average amount of dust in the atmosphere inhaled by these people over the yeen of their employment. Consequently, it is not possible to correlate individual eases with definite amounts of dust exposure. 'Moxtautt Experience Asiono Foundry Wonxxtu in United States and Great Britain Although this study did not Include the collection of Information relative to sickness among foundrymen, the Statistical and Actuarial Departments of the Metropolitan Life Insurance Company, in a study of mortality statistics, have supplied the following evidence to show that foundry workers are subject to an unusually high incidence of respiratory diseases. Mortality statistics both American and foreign, covering a long period of yean, agree In recording high death rates for respiratory diseases for foundry worken. These studies, it must be admitted, have been far from complete, giving little indication of the specific processes responsible for the excess mortality from these causes. Nevertheless, the results have been so consistent as to leave little doubt con cerning the presence of some condition v-4s VV s*. .<o1, *A a I- ^ r-I o--JI t.:: C> od i --. s> :2 o ;ros n H o cx w *in3 *3 3 July, 1934] HEALTH HAZARDS IN FOUNDRY INDUSTRY 239 t >! ra 55 * R r I i i * ' 14 240 THE JOURNAL OF INDUSTRIAL HYGIENE [xvi, no. J firmation of Americas insurance ex able to select not only workers who are perience is afforded by this compre skilled and competent, but also those hensive analysis of English population who are physically fit for the work. statistics covering the occupational This can only be accomplished through mortality of males in England and a physical examination, which should Wales during the year* 1021-1923. include an X-ray examination when Three classes of foundry worker* wen indicated. In view of the serious reported upon--metal (solders, Iron results frequently following long ex foundry fumaceman and laborers, posures in dusty atmospheres, alt siieh and brass foundry fumaeemen and men should be repeatedly re-examined laborers. Standardized death rates so that if evidence of disease develops (ages 20-65) were given for each of it can promptly be cheeked. the important causes of death. The foundry-men's mortality is shown to exceed that for all occupied Tee Lead Hazard m Foundries Studied and retired males for each of the Three of the foundries studied, J, K, respiratory diseases. So*far as re and 0, have brass foundries for the spiratory tuberculosis is concerned, easting of bearing metal. Air samples the excess was slight in two of the taken at the breathing level of the classes, being but 7 per cent, in excess workmen and analyzed for lead showed for metal molders, and 1 per cent for the concentration! given in Table iron foundry fumaeemen and laborers. VII. The rate for brass foundry fumaeemen Toxicity of lend.--A relatively small and laborers, however, was more than number of studies have been published twice that for all occupied and retired concerning the quantitative aspects of mates. Brass foundry workers, curi lead poisoning. Legge and Goadby ously enough, also hied the highest have stated as their belief that 2 mg. of death rates for each of the other lead was the lowest dose which, in-' respiratory diseases. Their death rate haled by a worker each day, would in for bronchitis exceeded the average by the course of a year set up chronic lead 69 per cent., that for influenza by 121 poisoning. Telelcy, a distinguished per cent., and that for pneumonia by German industrial hygienist, is re 146 per cent. Iron foundry workers ported by Oliver aa believing that a had the next highest death rates for tittle more than a milligram per day is each disease. Their excess mortality toxic. A recent investigation of lead ranged from 79 per cent, for influenza poisoning In a storage battery plant by to 127 per cent, for pneumonia. Russell et al. (14) indicates that the Metal molders had the lowest rate for limit of safety under the conditions each class except for tuberculosis. encountered in the study is an atmos Their rates for non-tubcreulous respir pheric concentration of lead dust or atory diseases exceeded the average fumes of less than Iff mg. per 10 cubic by from 41 per cent, for influenza, to meters of air. 72 per cent, for bronchitis. For the purpose of such a study aa As a protection to the employer aa the present, it is necessary to set rather well as the employees, it seems advis arbitrarily some standard for the I'j ^ July, I83il HEALTH HAZARDS IN FOUNDRY INDUSTRY 247 minimal toxic dose, and it is presum ably fair to assume 1 mg. per day as tbe minimal toxic dose. It is assumed that a man working ten hours inhales 10 cubic meters of air. All of this air would not reach the alveoii of the lungs, but this air would be drawn into the body and some of the dust or fumes dream with it might he swallowed if not inhaled. Men exposed to lead should be examined at monthly intervals. An Important part of the physical exami nation ia an examination of the blood. Most of the recent research workers regard the blood and the blood forming Lead may cause the early development of arteriosclerosis (hardening of the arteries) or chronic nephritis (lddaey disease), as well as other degenerative changes which bear no apparent rela tion to lead poisoning. There are four signs which most frequently appear during the early stage of the diMiMi (a) the tthan color of the aids, (b) the lead line on the gums, (e) stippling of tbe red blood cells, and (d) mild secondary anemia or other evidence of rapid peripheral destruc tion of blood, such as increased quan tity of blood pigment in the plasma or of hematoporphyrin in the urine. TABLE VII !1 RUfUAia niiim Vlf Wflf uuxiatAtfs 99 ttsim Wifi ItmbuiBsueiaisuritMait?inamr MltfVOU* Plant J..................................... 34.* 0.06 2.11 Plant K.................................... so.o 0.03 0.71 Plant Os,.................................... 74.5 0.04 1.41 21.1 7.1 14.1 system as the anatomical elements These conditions can onlybe discovered earliest affected by lead, and hold thaf by careful and frequent medical exam by a microscopical examination of the inations of exposed individuals. blood of )ead workers, lead absorption Certain measures of hygiene are may be detected before symptoms particularly important. Workmen develop, and when, therefore, it la should wear clean clothes while et possiblo for actual lead poisoning to work, and always keep them quite be averted. Additional evidence of separate from those worn at other absorption is the presence of lead in the time*. This requires two lockers, for exereta npd the appearance of a lead if dusty clothes are hung at night line in the gums. While neither the where street clothes hang during tbe presence of lead in the urine and fcccs, day, contamination can hardly be nor the discoloration of the gome prevented. An- excellent arrangement demonstrates in itself that there has used by many plants consists in build been any injury to the organism, both ing locker rooms on either side of the signify that lead has been absorbed. shower room. Men are required to Damage to body tissues may become leave work clothing in one locker and manifest in many different ways.' pea into the shower room. After \ mmm \ ; K g Hi a ri S 3 348 THE JOURNAL OF INDUSTRIAL HYGIENE (, no. 4 taking a shower they pass along to the certain foundries employing hydraulic next locker room where they drew in pressure in core easting cleaning. trcet clothes. Smoking or chewing Protective clothing should be worn tobacco, if the hands am at all dirty, by workers so exposed. involves the danger of ingestion of lead; and as food may also be con* Plant HopasxEErmo taminated In the same way, provision Orderliness and cleanliness, in to fsr should bo made for ample washing a practicable for the type of work, facilities and for eating In rooms were the rule rather than the exception completely removed from the lead in the plants studied. The floors hazard. were found to be fairly level. Only The physician or some representa occasionally were sandy hills and tive of the company should bo given hollows noticed. For cleaning, safety authority to order the transfer of and efficiency, concrete, wooden blocks suspicious cases from hazardous posi or granite blocks are preferable, and tions, or to request a period of rest. it is easier to keep them free from Upon re-exposure great emphasis must excessive dust. It is important to be placed on the necessary precau keep the aisles clear and well main tions, and the factory physician should tained, and provision should be made be rigorous in his supervision. for storing equipment and tools not Heat, Colo and Wet Hataint in use. Molders are exposed to the heat of Personal Service Facilities molten metal when pouring and again Washing facility.--Separate and to the heat of the partially cooled modem washrooms are provided for casting on shaking out the molds. the employees in most Instances. .Ih Cranemen and those working at the some the washing facilities are scanty cupola are exposed to excessive heat and inadequate. Shower baths pro from the molten metal, and it is usually vided with hot and cold water were the front of the body that is exposed. . found only occasionally. Here also arises a haxard affecting the Loektrt. The majority of the found eyes due to glare of hot metal and ries furnish lockers of some sort, made bums from spattering. either of wood or steel Aa the foundry is of a large area When employees change their street with large entrance doors and, neces clothing in the work rooms, the want sarily, has sources of heat unevenly of lockers leads to the continued distributed, drafts are set up to which exposure to dust of street clothing, as the workmen are exposed. The results wed as of food and tobacco, as long as of a study of the effects of radiant they are in the foundry. Because heat on the skin are reported in lockers and locker rooms are not Reprint No. 1370 of the U. 8. Public provided, the employees in many Health Service (15). This study dem cases wear their work clothes from onstrates the actual akin temperatures their homes to the foundry and back resulting from exposure to heat sources. again, and in this manner cany dust There am few wet hazards, except in into their homes. July, 1934} HEALTH HAZARDS IN FOUNDRY INDUSTRY 245 engaged in each foundry occupation, Cautu of death by occupation (12).-- assuming that they experienced the The occupational mortality of adult same death rate as Standard lives, was-- > white male Industrial policyholders computed. The number of expected of the Metropolitan Life Insurance deaths thus calculated was then com* Company who died during the years pared with the number which actually 1922-1924 is reported upon in this oesurred. investigation. Sines the number of Iron and steel moldcre, founders, tiring policyholders in eaeh occupation and casters, constitute the largest class was not known, death rates could foundry group represented in the not be calculated. The method of investigation. In fact, this is the analysis employed was to compare the only group reported upon which of proportion of deaths duo to any one itself had a sufficient number of deaths* cause to any one specified occupation to give significant results. It is group, with the proportion due to the worthy of mention first that more same cause among all occupied white deaths were recorded from pneumonia males. among these workers than from any Here again we find that pneumonia other cause. Where there might have was the leading cause of death among been expected twelve deaths from this foundry workers, a condition not true cause, there were actually 38, giving a of any of the other 71 occupations ratio of actual to expected deaths of included in the analysis. Deaths from 315 per cent. Twenty-four deaths pneumonia accounted for 15.9 per were recorded for respiratory tubercu cent, of the deaths from all causes, losis where 13 might have been ex while deaths from tuberculosis ac pected, giving a ratio of 170 per cent., counted for 14.6 per cent. The com while the ratio for influents was 216 bined group of respiratory per cent., based on 23 actual as com was responsible for slightly more than pared with 11 expected deaths. A ono-third of all the deaths of foundry- similar situation was found for mold- men, compared with slightly less than era, founders and casters of brass and one-fourth of the deaths of all occupied brorue, except that the ratios' in workers. general were higher than for iron When differences in the age com molders and deaths from tuberculosis position of the two groups were taken were more numerous than from pneu into account, it was determined that monia. The number of deaths, how the proportion of deaths from pneu ever, were few. There were seven monia was 120 per cent, higher for deaths from tuberculosis where 113 was foundrymen than for occupied males expected; five from pneumonia where generally. In the same way, the 1.1 was expected, and four deaths from proportion of deaths from influenza influenza where one was expected. was found to be 82 per cent, higher, All (he other foundry occupations that for tuberculosis of the respiratory showed high ratios of actual to ex system 5 per cent, higher, and that for pected deaths for each of the respira other respiratory diseases, 17 per cent. tory causes. Few deaths were re . higher. corded for each class, but taken Report of the requtrar-yentrai of together the results are significant. England and WaUt--IBtl (13).--Con- v. % It July, 19341 HEALTH HAZARDS IN FOUNDRY INDUSTRY 249 Water rup-ply and drinking faeili- only two plants (C and L) of the grey liet.--In the foundries studied city iron foundries and.three (R, S, and U) water supply was available. A few of of the malleable foundries were the the foundries have "bubblers'' or dust counts found consistently low. fountains. The water is eooled for The dust concentration in many use in the warm weather. instances was sufficiently high to Teiiris.--The toilets are all eon* justify the assumption that workers so neeted with a sewer system and are of a exposed over a period of years might modern type. As a rule, they are readily develop silicosis. More than adequate in number. 56 per cent, of the samples collected Clothing.--Protective clothing and exceeded ten million dust particles and foundry shoes are usually worn by the nearly 10 per cent, exceeded one workers. 'hundred million particles less than ten Rotpiraiort. These are ^provided microns in greatest diameter per where necessary and while a few work* cubic foot of air, determined by the rs use the old type cl helmet, the standard light field method. The majority use the' newer positive pres advantages of modifying the illumina sure air masks. The chief .criticisms tion (dark field method) are discussed to be made are: and the method described. Both 1. Poor mechanical maintenance; methods were used in this study and either the workman does not receive it was found that for dusts encountered sufficient air or else the face piece or in foundries the dark field method hood is so worn that it does not fit gave results consistently twice as properly. great as the standard light field pro 2. Use of an improper type of cedure. Counts determined by tho respirator--the use of the ordinary pig standard light field method only are snout respirator without positive air listed. supply. The report emphasises the harmful 3. Positive pressure respirators not effects on the lungs of exposed workers supplied with clean air. from inhalation of dust and gives the SmtuABT and Conclusions results of the X-ray findings of groups of workers. Sixty-seven of the two This study has directed attention to hundred fifteen X-ray films taken were the improvements noticed in foundry diagnosed as positive for silicosis. processes and particularly the progress While advanced eases of silicosis were made in the development of protoo- not found among those examined, tive equipment for foundry use. It de sufficient evidence of the occurrence monstrates also that the available pro of the disease is presented. The tective equipment either is not used prevalence of respiratory diseases, as to advantage or is poorly maintained. indicated by mortality statistics, is Counts of dust particles in the air discussed. taken at the breathing levels of the A section of the report is devoted workers are given and indicate a rela to a discussion of lead dust and fumes tively high dust count in practically found in a few of the foundries studied. every department of the foundry. In In every instance the lead content of I I I I W w $ wmm mmmmm I t. . 4 250 THE JOURNAL OF INDUSTRIAL HYGIENE [*, no. 4 the air breathed by workmen exceeded the limits of safety. Recommends* tions regarding the control of this hsurd are suggested. Other possible health hstsrds, such ss heat, cold, dampness, etc., have been briefly discussed. Comments re garding pleat housekeeping and per* sons! service facilities are made. Recommendations regarding the iso lation of processes, the use of approved equipment, responsibility for main taining end inspecting equipment, the desirability of a program to insure plant cleanliness, and the protection of workers by means of proper clothing and respirators and by initial and periodical physical examinations have been submitted. , It is believed that this study justifies the conclusion that white foundry work at present may be considered a hazardous occupation, there are avail able well-designed equipment and protective devices which, if used and maintained, will prevent undue ex posure of foundiymen to hazards injurious to health. BIBLIOGRAPHY 1. U. 8. PabUe Health Berries, Treasury Department, Public Health BuUetia No. 144: Comparative Tacts of Iastru- meats for Dctemiaiag Atmospheric Dust. Goremmsat Primtlag Offiee, Washington, D. C., Jaauary, 1021, p.41. 2. Dtniti, Pmur, in Tsousoir, Ron- car M.: Determination of Suapoasoids by Alternating-Current Pre cipitators. Tare Joua., June, J92S, . 7, No. , p. 281. X. Qtux, Hbs*t: A Photomicrographle Method for the Determination of Paitielt Siso of Paint aad Rubber Plgmenta. Jour. PraaUia lost., No vember, 1021. .4. Warms,G.C.: Vital Statistics. John Wiley A Bono, New York, W25,*. 4(1. t. HtrrsaxAK, P., am Oaamr, A. T.: The Method of Aetloa of Silica Dust in the Lungs. Tam loom., 1928, JO, 272. A V. 8. Public Health Service, Treasury Deportment, Public Health Reports March 18, 1932, VL 4T, No. IS: Tho lmpieger Dot Sampling Apparatus as Used by tho U. 3. PubUt Health 8ervieo. Government Printing Office, Washington, D. C. * 7. U. 8. Public Health Service, Treasury Department, Pulille Health BullaUa No. 117: Tho Health of Wortets in Dusty Trades, II, Rspeoun to Sili ceous Dust (Grunito Udtmtry). Government Printing OSes, Wash ington, D. C., July, 1020. A Pan'll, J. W.; IIL A Study of SDiea Dust in Hard Reek Drilling in New York City. Tms Joan., February, 1929, It, No. A P- 00. 9. Lana, A. J., am Canao, 8. B.: Min ers' Consumption,. A Study of 433 Catos of tho Diissso Among Zinc Minors in Southwestern Missouri, with o chapter on roentgen-ray findings in miners' eensumptiom U. S. Pub. Health Service Bulletin No. IS, Government Printing Office, Washington, D. C., January, 1917, p.2A 1A Committee on Group Mortality Investi gation, K. E. Cammack. Vice Prtsidsat aad Actuary, Astaa Life lasuraaee Company, Chairman: Com bined Group Mortality Experience 1022-1930, July, 19)1. 11. Actuarial Society of America aad Asso ciation of Life Insurance Medical Directors, N. Y. Joint Occupation Study--IMS, July, 1920. 12. O. 8. Bureau of Labor Statistics, Bul letin No. 807: Causes of Death by Occupation, Experience of Mctrapoli* tan Ufa Insurance Company indus trial Department 1922-1924. Louie I. Dublie and R. J. Vtae. Oovererwent Meting Office, Washington, D. C., Feb. 1H0. U. Rogistrar-Goaortl Xogiand and Woles, m %.cr.. 234 THE JOURNAL OF INDUSTRIAL HYGIENE [rri, no. 4 those exposed 20 yean and longer, and a large proportion of the worker* developed pulmonary tuberculosis. It was not found in this investigation that it would be necessary to eliminate nil of the dust to do away with the hazard. A safe limit of between nine and twenty million particles of dust, less than 10 microns in longest diam eter, per cubic foot of air could be established. The conditions of at mosphere involved in this investiga tion, however, are not comparable to those encountered in the foundries. Table I gives the dust counts by plants and by processes for the various types of foundries. These counts represent the air dustiness at a given place and for a given period during which the collect ing device was in operation, and merely suggest the extent of atmospheric pollution. It must be remembered, however, that these conditions may vary during the working day period and from day to day. The value of dust determinations lies in their employment as a measure ment for the efficiency of devices and equipment designed to control dust, rather than for the purpose of estab lishing safe limits of air dustiness. It will be noticed that the counts listed under plant L are consistently a lower than those under other grey iron foundries, and are entirely due to the progress this plant baa made in control ling the dust through well designed equipment and effective exhaust sys tems. A safe limit of air dustiness for foundries has never been established, but presumably on account of the high silica content of the dust the count representing a safe limit would be com parative!/ iow and in many instances impracticable to maintain. Protec tion can best be afforded to foundrymen by isolating dusty processes as far as practicable; by the employment of well designed and well constructed dust-tight equipment; by the substi tution, wherover possible, of mechani cal cleaning for hand cleaning; by the adequate maintenance of general ventilation and local exhaust systems; by good housekeeping; and by supply ing workers exposed to dust, which cannot otherwise be controlled, with adequate respiratory protective equip ment. Responsibility does not end with the installation of proper facili ties, but these must be adequately maintained through regular and intel ligent inspection. A responsible per son or persons directly under the supervision of the management should be assigned the task qf inspecting equipment and supervising house keeping conditions. X-bay Examinations .' Although certain symptoms and signs suggestive of silicosis may be found on physical examination, the diagnosis rests mainly on the X-ray film of the chest The progress of silicosis has been classified by Lanza and Childs (0) based upon roentgenray findings into three stages. The appearances during the progress of the condition are so strikingly different that anyone is likely to select practi cally the same classification. The first stage demonstrates a beginning fibro sis; the trunk shadows are increased in density and .breadth, with numerous punctata deposits of varying size along thpm. Second stage: in addition to the foregoing, there are found fairly \ OL. J. TsO. 2 INDUSTRIAL MEDICINE Page 79 characteristic picture of advanced ulieosis. An excellent x-ray film of the nor* rr.al individual's chest represents a projection of the pulmonary structure cast as shadows of varying density. Prominent among these densities are those cast by the blood vessels, which t(impose the so-called vascular tree. The fibrous changes initiated by pure silica can be detected in the early staecs on a good roentgenogram, by me increased densities shown at the root of the lung where the lymph nodes are situated. Further changes inrouchout the lymphatic system will become evident by an increased prominence of the vascular shadows caused by fibrosis developing in the lymphatics surrounding these struc tures. Finally the roentgenogram will reveal, as small round densities, the uniformly-distributed, discreet, lihrnus nodules present throughout the lung in advanced silicosis, giving the characteristic "snow-storm" ap pearance described by roentgenolojtlSiS. Inert dusts such as coal, hematite, gypsum. alumina, and limestone, pro duce no stimulation of the phago cytes and hence tend to remain with in these cells for long periods without prnmoiing any further action. When mixtures of silica and these inert busts arc inhaled together, the reac tion characteristic of silica is modi* msI by the inert material which umds to siow down the changes which would result if the silica were present alone. These modified reactions are apparent not only to the pathologist, but also to the roentgenologist, and constitute the great bulk of all eases of occupational fibrosis. Experience has demonstrated that Individuals with modified silicosis do not suffer fmm_ the excessive mortality which characterizes those groups with true Silicosis. ft tubercle bacilli are inhaled, they arc handled in much the same man ner, as dusts. Once in contact with tiits tissues, however, they are either killed and disposed of or they set up lucniizcd foci of infection. The oritamsms are transported by phago cytes into the lymphatics and the tis sues then attempt to wall off these fnci at infection by laying down an cwr thickening mantle of fibrosis. This reaction is much the same as that which follows the inhalation of 'Mica, except that it is generally lo calized to one or more portions of the lung and may be visualized and inirrprctcd as tuberculosis with re markable accuracy in a good x-ray t the chest. Obviously, the lung which has been injured by a pulmonary infection, iirh as tuberculosis, is far less com petent to deal with a dust, such as silica, than is the normal lung. Morevcr. it has been proved both clinl`-.iily and experimentally that the ln.':.i iu non of pure crystalline silica mis to reactivate a pulmonary tu' `Tcuious lesion which would other- heal, and frequently renders iis'ii infection progressive and fatal. Mvvn if the tuberculous lesion has successfully healed prior to the time when silica is inhaled, a far greatar reaction to the dust occurs about the <ite of the old tuberculous sear than xriirs in normal tissue, since the .lr.nn.ice system in that area has al- two processes apparently stimulate in workmen exposed to it over long the tissues to produce an excessive periods of time. Information gath amount of fibrosis. ered from field studies made in many Recent investigations have dis parts ol the world indicates that a nor closed that individuals who have mal man may work for many years simple silicosis, uncomplicated with in air containing pure crystalline sili tuberculosis, are r*t generally dis ca dust without impairing his health, abled. even though their condition providing the concentration docs not may be quite advanced. A careful- exceed 5.000.000 particles per cu. ft. physical examination frequently fails of air as determined by the standard to reveal anything abnormal about method used in the United States. such individuals, and the changes This concentration constitutes a which have occurred in their lungs special value for the health hazards can be detected only by the x-ray. created by silica which may be desig Silicotic workmen who complain of nated as the primary threshold. The shortness of breath, chest pain, cough, value of this threshold will be in or other disabling symptoms are gen creased for those industries in which erally found to have either a compli the silies hazard Is reduced by the cating pulmonary infection, usually presence of modifying factors. The tuberculous in nature, or some evi development rate does not always dence of a previous pulmonary in appear to vary directly with the con jury which has left s localized scar. centration but increases slowly with These cases esn be discerned on an the elevation of the dust, level up to x-ray film by the characteristic ap- a certain value where the accelera pearance of silicosis to which have tion becomes very marked. been added the densities cast by the Concentrations of 100,000.000 or localized masses of pulmonary fibrosis more pure silica particles per cu. ft. which exist about the sites of the in of air appear to be extremely hazard fection or previous pulmonary injury. ous and constitute a second special Frequently, such cases fail to show value which may be designated as the tubercle bscilli In the sputum until secondary threshold. Concentrations shortly before desth. In many In of pure silica above this secondary stances, the disease is unusually threshold lead to the rapid develop chronic and only slowly progressive, ment of silicosis and men working in manifesting itself largely by a pro these extra hazardous atmospheres gressive shortness of breath. Cases have been known to acquire true sili of this type are the prominent feature cosis in less than two years. Exam among the men actually disabled by ples of this type can be found among a modified silicosis hazard. men dry drilling tunnels in quartz Widespread misconception .of the ' rock or sandblasting without protec disabling effects of uncomplicated tive equipment Demonstrable silico silicosis has arisen from the studies sis usually develops in workmen ea of early investigators who were un sed to pure silica in concentrations able to distinguish cases of silicosis tween the primary and secondary from those complicated with pulmon thresholds in from five to 30 or more ary tuberculosis or other infections years, depending upon the individ with the equipment or knowledge ual's susceptibility and the degree of then available. These earlier investi the exposure. gations revealed silicotics who dis- Experience has shown that dimin played shortness of breath, chest ishing a hazardous dust exposure re pain, cough, and other disabling sults in extending the time required symptoms which were ascribed to sili for silicosis to develop and that even cosis alone since tubercle bacilli when it does occur, there is generally could not be found in the sputum. It little evidence ol disability among should be realized, at the present the workmen who contract it. unless time however, that silicosis assumes they have a complicating pulmonary a serious position as an occupational Infection or other injury. All of the hazard largely because of Its effect on preceding remarks with regard to pulmonary Infections, predominately dust concentration apply only to those tubqgculous in character. individuals without pulmonary ab Though the foundry must always normalities. Thq presence of pul be considered as a dusty industry, the monary infections or other patholog nature of its operations are such as ical conditions generally alters the to induce, for the moat part, only a normal susceptibility of dust diseases. modified silicosis. Both mortality It appears to be true that the indi studies and clinical examinations of vidual with arrested tuberculosis foundry workers fall to disclose the might be subjected to a health hazard type of hazard associated wtth a pure In an atmosphere containing less silica exposure. Many men in ad than 5,000,000 particles of pure quartz vanced age groups who have spent dust per cu. ft of air; while he might their entire working Uvea In the suffer no ill effects from exposure to foundry industry are still capable fairly high concentration of inert workmen, suffering from no occupa dusts, such as coal, alumina, limestone tional disability, although most of or hematite. Obviously, the values them will be found to hsve some de given cannot be used arbitrarily to gree of pulmonary Abrosia. The measure the degree of any hazard or workmen who ere disabled by an oc to form the basis for legislative codes cupational fibrosis contracted in the of good practice but they serve as one foundry are generally those who ex of the aids in bringing a given dust hibit evidence of concurrent pulmon hazard under controt ary infection or other injury. It must What then are the responsibilities be recognized. In spite of these allevi of the executives of those industries ating circumstances, that s certain in which the dust hazard is suspected? occupational hazard does exist in all In the author's opinion, the first duty foundries. imposed upon the operator, requires Any working atmosphere which that he secure a thorough knowledge contains more than a certain thresh- of the nature of the disease itself old Page SO INDUSTRIAL, MEDICINE February, 1936 jcct. unfortunately. assume the atti tude that silicosis is just another "racket" and delegate the duty ot keeping the organisation out of trou ble to minor officials. The subordinate officers, having been impressed with the general attitude of the manage ment. are frequently powerless to inaugurate a comprehensive program designed to cope with all of the exist ing circumstances and delay construc tive action by refusing to recognize that their operations are in any way affected. The futility of this procedure is evi denced by the fact that claims event ually uriae wnieh eompel recognition of the disease and the adoption of a proper policy at a time when condi tions are much less favorable for its successful application than would have existed at an earlier date. Some managements apparently re gard the silicosis question as a purely legal matter and rely largely on such counsel for determination of policy. This procedure tends to distort the problem by illuminating it largely from a single aspect. Obviously, it is equally inadvisable tor a manage ment to depend entirely upon the judgment or suggestions offered by either the medical, engineering or production members of its staff. The most important requisite to good administration of silicosis prob lems lies rather in an informed man- agment advised and directed by au thoritative opinion representing the legal, medical, engineering and pro duction divisions of the industry and assisted by consultation with some or ganization qualified bv long experi ence with the problem, if necessary. Having divested themselves ot pre formed conclusions concerning their particular situation, the second re sponsibility of employers consists in inaugurating a thorough survey of their plant to determine the existence, nature and extent of the dust hazard. A survey of this type may include the physical and x-ray examination of the employees, the taking of occupational records, the determination of the nature and concentration of the dust suspended in the working atmosphere, an analysis of the mortality records in the district, and if possible, post mortem examinations of old em ployees dying from any cause. The actual Importance of silicosis as an industrial problem has been greatly over-emphasized for several reasons, chief among which has been the reluctance of administrative of ficers to investigate and reveal the existing facts in their operations. The mantle of secrecy which has shrouded existing conditions wherever many ' dust hazards are involved, has served to exaggerate their significance. Cou pled with this lack ot accurate and complete information, there has beat, in the United States, an unwilling ness to provide well-framed legisla tion to regulate the compensation ot workmen affected by exposure to dust. This, in turn, has resulted In the filing ot numerous claims In civil court which allege that a personal in jury has been Incurred through the negligence of the employer in per mitting men to work in a hazardous atmosphere. The enormous amount of mangy involved in these civil actions, to- -------'-------------- V... judicial bodies attempting to deal with this complex question, has given an altogether unwarranted notoriety and importance to this subject. Un favorable experience with civil ac tions has prompted the hasty passage of occupational disease legislation in some ot the United States where the facts are still unrevealed, and there is every reason to expect that unrea sonable decisions based upon poor medical testimony, misinformation concerning the dust hazard, and a general tendency to attribute all ills to industrial conditions, will tend to discredit these laws and thus further prolong the unusual prominence, ac corded silicosis. Administrative officers must fur ther recognize that the situation which has been created in the United States is now of an emergency nature, and that there is neither a sufficient amount of reliable information, nor a .large enough number of properly trained and informed authorities in many localities to deal with the sili cosis problem. Under the press of emergency, many so-called silicosis experts have appeared over night and technical publications have been flooded with silicosis articles, few of which have added materially to the general understanding of the subject, but many of which have served to confuse and confound everyone in terested in evaluating the actual issue. As is true of nearly all diseases known to the science of medicine, cer tain phenomena associated with dust diseases are not understood or arc imperfectly explained by medical au thorities. A much more unfortunate difficulty arises out ot the fact that many members of the medical profes sion, whose authority cannot be ques tioned in their particular field, ere er roneously Informed on this subject and offer opinions which are ac cepted as true, to the further bewil derment of all. The same criticism may be offered against engineers, public health of ficials or attorneys, whose knowledge ot silicosis has not arisen out of long and Intimate first-hand experience. For this reason. It may be advisable to consider consultation with some organization competent to analyse the Information available so that a proper policy may be determined. U no hazard is discovered by a thorough survey, both the employer and the employee are protected by the information secured. On the other hand. U a hazard Is detected, the orig inal study serves as a guide to the fu ture program of control which should be promptly initiated. A control program in a dusty in dustry whose hazard has been defined will include the reduction ot the dust concentration in the working atmos phere and the application of orotectlve devices, the establishment of cer tain physical standards for new em ployees, the selective placepsent of old employees on the basis ot their physical condition and the adoption of an educational program properly to inform all those vitally concerned with the effects of a dust hazard. Thoroughly reliable methods of de termining dust concentrations are available and engineers equipped to utilize these procedures can discover h .rmrr-- and extent of the contam- during the hazard to within safe limits or applying adequate protec tive devices. A constant check of the dust concentration in the atmosphere should be maintained and records should be kept to show the condition of the working atmosphere, the na ture of the protective equipment and the total duration of time each work man is required to spend in a hazard ous occupation. A pre-employment examination, including an occupational history and excellent stereoscopic chest roent genograms, should be given to every new employee. In general these ex aminations will serve to classify men lnte three main groups eampoaod at (1) those whose cheats are appar ently normal, (2) those who have an occupational Abrosis without any other pulmonary abnormality, and (3) those who have tuberculosis or other pulmonary abnormalities either with or without occupational fibrosis. In considering the desirability of employing men whose chests are ap parently normal, it should be borne in mind that young men. probably up to the sge of thirty or thereabout, are not altogether perfect risks for em ployment in a hazardous dust since they are in an age period during which they may atiU contract tu berculosis. In the author's opinion, men who show evidence of simple occupational fibrosis and who are past the age of 30, as most of them will be. are ex cellent risks since the author does not believe that uncomplicated silico sis is ordinarily disabling and since thesa men are past the age period during which they are likely to de velop tuberculosis. These men may show tome progression of their fibro sis after employment in a dusty in dustry but they will not tend to de velop disability if they have been rig idly examined to exclude those show ing any x-ray evidence of tuberculo-. aia or other pulmonary injuries. If this class of persons is to be dis criminated against, it will create a most unfortunate social problem, since many skilled craftsmen perfect ly capable of a lifetime of useful ac tivity will be thrown out of work lo become embittered and the prey o( unscrupulous lawyers and doctors who will further complicate the sit uation by making the . workmen claimanta and neurotica. It is the au thor's belief that these men should not be eligible for compensation but if they are made so under the law, then legislation should also be provided to permit them to waive their right to compensation for an occupational disease, so that they may have the privilege which should be accorded to all free men--that of working at the tasks for which they are best suited. Provided that this group is carefully selected to exclude infection and remains under medical supervi sion while in the dusty industry, their experience should be as favorable as any that the employer could choose. As to the third group of men. an injustice is done to both the employer and the prospective employee bj placing any person at work in a haz ardous dust who has tuberculosis or other significant pulmonary abnor malities whether or not occupational fibrosis is present. In the presence of a known dusi